Valachi told what he knew, but in reality, he was too low down in the organization to know a lot. But the FBI ate it all up because they had almost nothing on the inner workings of the Mafia--Hoover simply ignored the Mob until that time.

"Underboss" was an interesting read. Exposed the mind of a psychopathic killer.

"I Hear You Paint Houses" is interesting about how Sheeran got involved with Hoffa, and does shed some light on Russell Bufalino. But it promises to expose Hoffa's killing, and comes up just short. Keep in mind that it was published after Sheeran died.